I recently replaced my home network and have had issues connecting to the Unraid GUI ever since.

Previously Unraid was set with a static IP (192.168.68.66) and gateway (192.168.68.1) but in the new network I wanted to let it handle the IP assignment via DHCP, as this seems the better option. However, once I'd reset the Unraid Network Configuration to use DHCP and rebooted, I could no longer access the web GUI or even ping the NAS. Thankfully I could still access the GUI via a Tailscale IP after I lost access locally (so there was some sort of Internet access even after I changed the network config). I could SSH into Unraid too via Tailscale, and in testing I could see that some devices on the new network responded to pings but others didn't - I couldn't see any specific pattern to it.

I figured it was some sort of cache issue in the network, or Unraid, or my laptop, so I rebooted literally everything, multiple times. I still couldn't get to Unraid on the new IP, including from other devices.

Eventually I managed to get things working by going back to a static IP config on Unraid, and it worked fine with the new IP of 10.10.10.66 (which had been assigned via DHCP initially). With things configured this way the NAS responds to pings, and I can get to the GUI just fine. It's good to have access back, but I'd like to understand what happened and why Unraid doesn't seem to work with a normal DHCP config.

I thought at first it must be an issue with my config of the new network (Unifi), assuming I'd done something with firewalls/zones/vlans/etc. that blocked access. But as near as I could tell it all seemed fine. I figured it was a subnet issue, but then why would it work with the same IP in the same subnet when set to static IP in Unraid, but not DHCP?

I have seen lots of posts here in the Forums that suggest it could have been that something wasn't picked up when I changed the network config, and at least one that suggests that v7.1.2 may have been part of the problem (I updated a couple weeks ago). I stopped short of deleting /boot/config/network.cfg as I was worried I'd lose all access, but maybe that would have helped? Is there something I can to see if there is still some sort of prob in the net config?

Weirdly, before I regained access I noticed that when I rebooted Unraid, for just a few seconds early in the process the GUI would be accessible at the new DHCP-assigned IP, and the NAS would reply to pings. But after this short window it would go back to timing out when trying to access the GUI or pinging it.

When I first changed Unraid Network Configuration to DHCP, at least in the Unifi network everything looked OK: I could see the Unraid NAS had been assigned an IP in the new subnet (10.10.10.66). I set this as "Fixed" in Unifi. Logging into Unraid via Tailscale the Routing Table seemed to look OK to, with routes like this:

IPv4	default	10.10.10.1 via br0	1005
IPv4	10.10.10.0/24	br0	1005

I'd still really like to get Unraid working on DHCP normally so that if I move the NAS around in future I won't have to go through all this again. Any ideas?

Make sure you are not getting bit by this one:

This is found under SETTINGS >>> Management Access

EDIT::: Also log into your router and see if it assigning an IP address to your Unraid Server.

Edited May 26, 20251 yr by Frank1940

Hi @Frank1940, thanks for coming back so quickly on this.

I've had a look into the DNS rebinding issue, but I've got Use SSL/TLS set to no, as I'm accessing the Unraid server via a reverse proxy (so it just works as http://10.10.10.66 and Nginx takes care of the SSL). I don't think this would have entered into it anyway though, since I was unable to access the Unraid server even via it's IP directly (without relying on DNS).

The router definitely assigns an IP address, I've just triple checked.

I was unable to access the Unraid server directly at it's IP (the IP set by the DHCP server on the router), or even to ping the IP.

Strange indicators. When you have it set to receive dhcp address, are you able to verify locally and see wthe IP assigned, specifically br0? Also, does it act the same if you disable Tailscale? It 'feels' like either an IP conflict or maybe DNS. Distant 3rd would be firewall rules. If you have multiple nics try disable/disconnect all but one.

Hi, thanks for coming back on this @Veah

I've gone back to full DHCP (screenshot attached) and run ip addr to see what IP br0 was given:

host:~# ip addr show br0
7: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 24:97:ed:2d:41:83 brd ff:ff:ff:ff:ff:ff
    inet 10.10.90.66/24 brd 10.10.90.255 scope glo

Onice I did this I saw the same behaviour, where the local IP worked fine as a way to reach the Unraid UI for just a few seconds not long after reboot, and then it stopped working. The IP shown is the correct one that I have assigned to the NAS on the DHCP server. There's just the one nic on this device.

I'm loathe to disable Tailscale as for now it's the only easy way I can get to the server when this happens.

I've had another look at firewall rules but I don't think this is the problem, mainly because I'm on the same subnet as the Unraid NAS and can reach another server also on the subnet just fine. I guess there could be some unintentional rule blocking it but I sure can't find anything.